Method of validating a diagnostic leak detection test for a fuel tank

摘要

A method of validating a leak detection test for a fuel tank in a vehicle includes the steps of determining a vacuum decay rate of a fuel vapor in the fuel tank and dividing the vacuum decay rate into a set of adjacent segments distributed over a series of consecutive time intervals. The method also includes the steps of determining a slope of the segments, determining if a difference between two consecutive slopes of the segments meets a predetermined criteria, and validating the leak detection test if the difference meets the predetermined criteria.